The effectiveness of tobacco cessation programs for university students: A systematic review and meta-analysis

INTRODUCTION This systematic review and meta-analysis aimed to explore the existing tobacco interventions and synthesize whether those interventions affected tobacco use among university students. METHODS We searched and found 1799 studies in PubMed, ClinicalKey for Nursing, Embase, and SCOPUS between 2009 and 2022. The risk of bias was assessed using similar criteria for RCT and non-randomized studies guided by the Cochrane Handbook for Systematic Reviews. The heterogeneity of studies was evaluated using Cochran’s Q and I2 index. The GRADE system was used to distinguish the quality of evidence, and Egger’s linear regression test was performed to assess publication bias. RESULTS Eighteen studies used data extraction and analyses, and only eleven were meta-analyzed, which found that the estimate obtained via the fixed-effects model was statistically significant. Technology-based and motivational interview interventions found pooled ORs of statical significance, while reinforcer interventions showed the smallest effect size. The level of heterogeneity was considered substantial. The assessment for quality of evidence showed low overall certainty of evidence due to imprecision of outcome and suspicion of publication bias. Egger’s test showed no publication bias among included studies (p=0.38). CONCLUSIONS There were numerous tobacco cessation interventions for university students, but the most effective intervention to change tobacco consumption behavior was still inconclusive and uncertain. TRIAL REGISTRATION This systematic review was registered with PROSPERO. The registration number is CRD42019142491.


INTRODUCTION
Tobacco use is one of the leading causes of chronic diseases and mortality worldwide. Despite governments implementing robust tobacco control policies, tobacco causes the premature death of more than 8 million of the world's population yearly, especially in low-and middle-income populations 1 . Several strategies for tobacco cessation have been used. They include creating smokefree environments, educational campaigns, quitlines, air quality policies, face-toface sessions, mobile web-based applications, and blended strategies [2][3][4] . Outcomes varied from cognitive changes, such as knowledge, to behavior changes, such as refraining from smoking initiation or quitting smoking [5][6][7] . Most interventions have been designed to motivate and assist people in stopping tobacco use in adolescence and as adults in community settings, schools, and workplaces [5][6][7][8] .
Consequently, a reduction in the overall prevalence of tobacco use has occurred in many countries.
Tobacco use among youth is now an alarming trend in some countries 9 . Specifically, in two-thirds of 31 countries where data are available, more than 30% of current smokers started smoking daily by the age of 16 years 10 or among young people aged 15-24 years globally. The average rate of tobacco use worldwide was 17.0% in 2015 and has tended to increase every year 11 . Noticeably, the literature reviews regarding tobacco cessation programs specifically tailored and applicable to solve university or college students' unique tobacco use issues are limited.
This systematic review and meta-analysis aimed to explore the existing type of tobacco interventions and synthesize whether those interventions had any effect on tobacco use among university students.

Data sources and search strategies
This systematic review was registered with PROSPERO, the prospective international register of systematic reviews. The registration number was CRD42019142491 on 23 October 2019. Articles published from 2009-2022 were searched in PubMed, ClinicalKey for Nursing, Embase, and SCOPUS.
To be included in this review, a study followed the PICO key terms, and all words were based on medical subject headings (Mesh): • Population (P): university students, college students, undergraduate student • Intervention(s) (I): tobacco product use, smoking, cigarette smoking, waterpipe tobacco, electronic cigarettes, chewing tobacco, hookah tobacco, and dokha • Comparator(s) (C): the group that received no intervention or control group. • Outcomes (O): tobacco cessation, quit cigarette smoking

Eligible studies
Articles searched were restricted to articles in English published as full text, including randomized controlled trials or quasi-experimental studies, with no age or Figure 1. PRISMA flowchart of study selection search stage. After duplicates were removed and titles and abstracts screened, 1646 records were excluded. Eighty-one full-text articles were retrieved and assessed for eligibility. Then, 60 articles were excluded after reading the full-text articles. Twentyone articles were evaluated for data quality, and another three were excluded on critical appraisal due to methodology incongruity with the review. Finally, 18 articles were included in the systematic review and meta-analysis.

Types of intervention Technology-based approach
Half of the included studies (9 out of 18 studies) selected technology-based smoking cessation interventions, comprising four mobile text messaging 16,18,19,28 , a web platform 27 , an automated web-phone intervention 21 , a smartphone application for smoking cessation 15 , a peer-based social, mobile game intervention 17 , and a computerized motivational feedback program 14 . The details of each technologybased smoking cessation intervention are described below.
The elements of mobile text messages differ across studies. Features included making a public declaration about quitting (i.e. telling friends about the quit attempt), asking friends and relatives for support, using problem-solving tips and distraction techniques, and the option to text for more help if craving to smoke or smoking 19 . In addition, there was an option to request extra messages in some interventions if subjects had cravings to smoke, relapsing, or concerns about weight gain 16,18,19 .
The smartphone application named 'Quit with US' consisted of five main pages designed to help university/college students quit smoking, including: 1) offering information regarding the disadvantages of tobacco smoking and recommending to quit (Suggested by US); 2) arranging the follow-up communication with experienced pharmacists (Talk with US); 3) assessing and assisting quitting smoking with a personalized quit plan (Quit with US); 4) helping to quit smoking by suggesting coping methods for nicotine craving and unintentional smoking (Let US help); and 5) arranging a self-monitoring of quitting smoking (Success of US) 15 .
An automated web-phone intervention system was used as a motivational/educational message delivered by phone calls. It aimed to assess participants' smoking status and provide motivational and educational recorded messages based on their responses 21 .
A peer-based social, mobile game intervention called HitnRun was designed to be played during individualized moments of high craving, stress, or boredom. The peer interaction was a game-based experience to support and reinforce desired smoking behavior. The participants in the game group were encouraged to play the game at least once per day, and tailored prompts were sent to keep them engaged with the intervention and remind them of the purpose of the game 17 .
A web platform-based intervention uploaded the information, images, and videos regarding the health risks and life experiences of ex-smokers. In addition, the web page provided a space where people could show their experience, recommend their ideas, and answer something in the open discussion forum 27 . Also, a computerized motivational feedback program used a two-staged treatment approach that combined a motivational engagement program and cognitivebehavior treatment (CBT)-oriented individual cessation counseling 14 .
Face-to-face approach Nine studies implemented this approach in various interventions, including a reinforcer intervention such as contingency management 23 , a Quit & Win contest 13 , three motivational interviews 20,22,29 , four health education-based programs [24][25][26]29 , and an acupressure intervention 30 as presented below.
Contingency management (CM) principally provides reinforcers contingent on abstinence or reduction of substance use as a set target. The critical components of CM include: 1) obtaining objective evidence of abstinence or another target behavior; 2) provisions of reinforcers, such as money or vouchers, when the target behavior is accomplished; and 3) withholding reinforcers when the target behavior does not occur 23 . The Quit & Win contest focused on abstinence from all tobacco products 13 .
Motivational interview (MI) was the single approach in three studies 20,22,29 and combined with other interventions to sustain the desired outcome of cessation 23 . One study implemented the session of MI that included a face-to-face 50-minute meeting that mainly reinforced the decision to change, elaborating a personal plan to stop smoking 20 . Another study conducted four one-on-one sessions of MI with a trained counsellor, and the contents were focused on motivation and assisting participants in quitting cigarette smoking 22 .
Health education-based programs were implemented at both individual 26,29 and campus/ institutional levels 24,25 . One study had two stages of a seven-session education. The first stage comprised three education sessions to develop an intention to quit tobacco use. The second stage included four education sessions to promote coping, recovery, coping, and action planning for smokers who wanted to quit 26 . One study implemented health education to impress students about tobacco-related health effects and tobacco cessation 29 . The other study used interprofessional learning among medicine, pharmacy, pharmacy technician, and public health students. Teaching activities included a short didactic lecture, videos on motivational interviewing, case scenarios, and group discussion 24 . Another study implemented a campus-wide smoking ban policy to create a campuswide smoking ban and attitude change among college students 25 . One study used an auricular acupressure technique with multimedia instruction guided by expert physicians who practice traditional Chinese medicine 30 .

Outcome measures
The primary outcomes of tobacco cessation programs across the included studies were diverse. The primary outcome was self-reported abstinence commonly measured in 7-day point-prevalence 14,15,[18][19][20] . Some studies evaluated the point prevalence of not having smoked a single cigarette or self-report of continuous abstinence widely measured over thirty days 13,18,19 . One study measured the most prolonged duration of constant abstinence in the past 12 months 26 . In contrast, one study measured the shortage of abstinence in only the last 24 hours 17 . Most of the included studies verified and confirmed tobacco use abstinence by biochemically verifying self-reported tobacco abstinence by detecting cotinine in urine 13,20 or saliva samples 14,[21][22][23] . Another way of abstinence verification and confirmation use was expired carbon monoxide (CO) after completing intervention or follow-up periods 14,15,23,30 .

Risk of bias within studies
The risk of bias was assessed using similar criteria for RCT and non-randomized studies guided by the Cochrane Handbook for Systematic Reviews of intervention 31 . One RCT study 23 and three studies of non-RCT 26,29,30 had some limitations in systematically randomizing the participants into intervention and control groups. In allocation concealment criteria, there were two non-RCT studies 29,30 and one RCT study 23 that did not conceal the allocation of the participants into intervention and control groups. Most of the included studies 13,15,17,19,20,22,23,26,29,30 needed to provide more information about the blinding of outcome assessment for authors to make a judgment regarding detection biases.
For attrition bias, some studies 13,[17][18][19]29 showed unclear completion of outcome data, whereas one study 26 did not mention the completion of outcome data. Lastly, there were only three studies 19,26,29 exhibiting unclear reporting bias, and one study 13 showed a high risk of reporting bias due to the study selecting data from another study to analyze and report only the perspective of hookah use ( Figure 2).

Meta-analysis
The forest plot for meta-analysis provides information to assess statistical heterogeneity, as shown in Figure  3. Eleven studies were included to compare the types of intervention effectiveness with non-intervention. The effects on tobacco cessation across the included studies are generally consistent and favor intervention over the non-intervention group, showing a statistical difference. The analysis detected high heterogeneity (I 2 =84%, p<0.001), and the estimate obtained via the fixed-effects model was statistically significant (OR=1.50; 95% CI: 1.30-1.73, p<0.001).
Subgroup analysis based on types of intervention found that the technology-based 15   As shown in Figure 5, when evaluating the effects of interventions by a group of RCT versus non-RCT, the pooled OR of eight RCTs 13,[17][18][19][20]22,23

Risk of bias across studies
The visual evaluation of publication bias revealed the asymmetrical distribution of the funnel plots. Most studies had larger sample and effect sizes, which might indicate publication bias in this review ( Figure 6). The funnel plot analysis of types of intervention shows an asymmetrical distribution in the reinforcer interventions and the motivational interview interventions. The Egger's regression test indicates no statistically significant publication bias among included studies (p=0.38). The assessment for quality of evidence showed low overall certainty of evidence due to the imprecision of outcome and suspicion of publication bias (Supplemenary file).  There were no significant differences of students who reported smoking at least one cigarette in the past 30days between the two school before or after the ban.
There was not a statistically significant decrease in percentage of students who had smoked ≥100 cigarettes in their lifetime, from 2014 to 2018.
Attitudes toward smoking, perceived smoking, and attitudes toward a campuswide smoking ban did improve significantly.

Quasi-intervention study
The education program was divided into two stages: 1) Motivation and volition.
2) The intervention group received seven sessions of education during these two stages, while the control group did not receive any education.
Intention to quit hookah Abstinence from tobacco use.
44.1% of intenders in the intervention group and 9.4% in the control group quitted hookah after 6 months of the intervention.
19 out of 71 students in intervention group and 6 out of 67 in control group successfully quitted hookah in 12 months after the intervention.
Romero-López at al. 27 2020 Nursing and Physiotherapy students who were regular smokers.
A two-phase pilot study was conducted: The first phase was cross-sectional, and the second phase was a before-and-after intervention.
An intervention based on the use of information technologies in the motivation to quit smoking.

Means of the Richmond questionnaire
Dependence on nicotine through the Fagerström questionnaire 3.45% of the participants had a high level of dependence; and 6.90%, a high level of motivation.
The level of motivation did not change after the intervention (p=0.10).
Scholten et al. 17  Rate of daily smoking declined (p<0.05) over time.
Competence need satisfaction, readiness to quit smoking and severity of nicotine addiction remained unchanged.
Smoking cessation self-efficacy was the strongest predictor of smoking behavior change in college students. A multi-component intervention including motivational interview and online self-help material to change student perception of tobacco and increase self-efficacy.
Proportion of students who stopped smoking.
Self-report,7-day abstinence from smoking at 6 months Urine cotinine analysis

Mean of smoked cigarettes
Quit attempts

Self-efficacy (SE)
Decisional balance After 4 weeks the participants in both the experimental group and comparison group improved on self-efficacy (SE) and stage of change (SOC) toward smoking cessation.
After another 5 weeks, their SE remained significantly improved, but SOC did not.

DISCUSSION
This systematic review and meta-analysis investigated the effects of interventions on tobacco cessation among university students. Eighteen studies met the inclusion criteria and their data extracted and analyzed, and 11 studies were eligible for metaanalysis. The findings indicated that the pooled effect sizes for RCTs were significant but small for tobacco cessation compared to the non-RCTs. Among the studies reviewed, technology-based and motivational interview interventions greatly affected tobacco cessation.
High heterogeneity in effect size was found when types of intervention were compared to non-intervention. This heterogenicity may have been caused by an artefactual variation such as improper randomization and differential followup. In addition, another cause of heterogeneity in systematic reviews is actual variation in the treatment effect, including intervention factors such as dose, timing, or duration of treatment, and timing and event type of outcome 32 . Based on the risk of bias assessment of this review, improper random sequence generation, improper allocation concealment, lack of blinding of outcome assessment, and incomplete outcome data were observed. Thus, developing an effective intervention that is specific to university students is challenging.
Although asymmetry of the funnel plots was found in the reinforcer and the motivational interview interventions, there are many reasons for asymmetry. First, the quality of the trial design affected the apparent result. For instance, improper allocation concealment is associated with odds ratios exaggerated by 41%, whereas lack of blinding of outcome assessment is associated with odds ratios exaggerated by 17% 33 .

Strengths and limitations
This study has several strengths. First, only RCT studies were included in this meta-analysis. Second, the number of participants was 8186 students, which allowed us to perform further analyses. Finally, this study assessed the risk of bias and the quality of evidence. However, this review is limited by the number of studies for meta-analysis due to differences in outcome measurement. Outcome measurements of tobacco cessation were also varied.

CONCLUSIONS
The overall trend in tobacco consumption among young people has increased remarkably in the past decade. University students are a significant group of the young population defined by setting, demonstrating a high tobacco consumption rate. An effective tobacco cessation intervention for them should be identified, and it is essential. The findings from this review revealed that there were numerous tobacco cessation interventions for university students. However, an effective intervention to change tobacco consumption behavior within this population is still inconclusive.